Week Forecast Forecast Error Week Patient Arrivals 1 2 3 4. 5 400 380 411 1 2 3 4 5 a. Reconsider the patient arrival data in Example 14.3. It is now the end of week 3 so the actual arrivals is known to be 411 patients. Using a = 0.90, calculate the exponential smoothing forecast for week 4. b. What was the forecast error for week 4 if the actual demand turned out to be 415? C. What is the forecast for week 5